The present invention is directed to a device to be worn by a human patient and more particularly to an external airway support to alleviate the airway obstruction of unconsciousness that may occur in a wide variety of circumstances such as sleep apnea, emergency treatment and transport of unconscious individuals and where sedation or anesthesia is employed.
Airway obstruction can occur in human beings during states of unconsciousness which can occur with natural sleep, as in sleep apnea, and with conditions of pathologically or pharmacologically produced decreases in consciousness. It is believed that there is a common mechanism underlying the airway occlusion in these circumstances. The obstruction is caused by a decrease in tone of the muscles of the pharynx, mandible (lower jaw) and neck. The overall effect of this decrease in muscle tone is a collapsing inward, and hence narrowing, of the upper airway. The most critical change, which can cause total airway obstruction, is the falling back of the tongue to occupy the pharyngeal air passage. This critical obstruction is believed to be caused by a decrease in the activity of the genioglossus muscle which connects the tongue to the point of the chin. This is most likely the cause of the common phenomenon of snoring as well as the potentially life threatening airway obstruction of sleep apnea.
Anesthesiologists are well aware of the problem of airway obstruction of unconscious patients as it invariably accompanies general anesthesia. Prior to the instant invention, the problem has been managed by manually lifting the lower jaw with slight extension of the head on the neck. This has the effect of lifting the tongue from the posterior pharyngeal wall to restore unobstruction of the airway.
The present invention will be of great value to the anesthesiologist in anesthesia practice since it can be used to maintain an unobstructed airway passage of the patient while freeing the anesthesiologist from the necessity of manually administering suitable treatment. It could be used to free the anesthesiologist's hands during the management of most spontaneously breathing non-intubated patients undergoing general anesthesia or sedation. It could also be used to allow airway maintenance in situations where manual airway support is impractical. Such situations can include surgery which is performed in the area of the patients head under heavy sedation, such as, for example in eye surgery or neurosurgery.
There are many other circumstances wherein the upper airway passage of a patient could become obstructed. For example, many, if not most, hospitalized patients receive sedation at one time or another. Sedation combined with debility can frequently lead to airway obstruction. Many cases of cardiac arrest in hospitals can be traced to this problem. These patients can be recognized by appearing asleep, head slumped unsupported, with mouth ajar and snoring. Another circumstance is in the emergency transport of unconscious individuals encountered by, for example, ambulance personnel wherein the unconsciousness of the individual being transported could cause an airway obstruction. Lastly, sleep apnea has been estimated as afflicting between 1 and 3% of the population. Very often it is of the obstructive type directly analogous to the problem seen in anesthesia and sedation wherein an obstruction in the upper air passage occurs due to loss of muscle tone with the onset of sleep.
Unfortunately, current treatments of sleep apnea and other forms of airway obstruction have included tracheostomy and a variety of major surgical modifications of the upper airway. A common conservative treatment has also been the use of a positive pressure breathing mask.
Hence, as can be seen from the above, there is a need in the art for an externally applied airway support to prevent obstruction of the upper airway passage in patients due to the onset of sleep or unconsciousness. Such a device must be simple, cost effective, and conservative in treatment to promote wide spread patient acceptability.